/*
    This file is part of the substandard lisp implementation of Standard Lisp
    Copyright (C) 2011 Nicky Nickell

    substandard lisp is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
    builtins related to property lists as defined in section 3.4 of the
    The Standard Lisp Report
*/

function std_flag(a, env) {
  var u = a[0];
  var v = a[1];

  for (var p = u; p != NIL; p = p.cdr) {
    if (type_check(p.car.type, TYPE_ID)) {
      p.car.flags[v.value] = true;
    } else {
      // raise an error?
    }
  }

  return NIL;
}
builtins['flag'] = new builtin_function(std_flag, 2, false, [TYPE_PAIR, TYPE_ID], FTYPE_EXPR);

function std_flagp(a, env) {
  var u = a[0];
  var v = a[1];

  if (type_check(u.type, TYPE_ID) && type_check(v.type, TYPE_ID)) {
    if (u.flags[v.value] != undefined) {
      return T;
    }
  }

  return NIL;
}
builtins['flagp'] = new builtin_function(std_flagp, 2, false, [CLASS_ANY, CLASS_ANY], FTYPE_EXPR);

function std_get(a, env) {
  var u = a[0];
  var ind = a[1];

  if (u.proplist[ind.value] != undefined) {
    return u.proplist[ind.value];
  } else {
    return NIL;
  }
}
builtins['get'] = new builtin_function(std_get, 2, false, [CLASS_ANY, CLASS_ANY], FTYPE_EXPR);

function std_put(a, env) {
  var u = a[0];
  var ind = a[1];
  var prop = a[2];

  u.proplist[ind.value] = prop;

  return prop;
}
builtins['put'] = new builtin_function(std_put, 3, false, [TYPE_ID, TYPE_ID, CLASS_ANY], FTYPE_EXPR);

function std_remflag(a, env) {
  var u = a[0];
  var v = a[1];

  for (var p = u; p != NIL; p = p.cdr) {
    if (type_check(p.car.type, TYPE_ID)) {
      delete p.car.flags[v.value];
    } else {
      // raise an error?
    }
  }

  return NIL;
}
builtins['remflag'] = new builtin_function(std_remflag, 2, false, [TYPE_PAIR, TYPE_ID], FTYPE_EXPR);

function std_remprop(a, env) {
  var u = a[0];
  var ind = a[1];

  if (u.proplist[ind.value] != undefined) {
    var val = u.proplist[ind.value];
    delete u.proplist[ind.value];
    return val;
  } else {
    return NIL;
  }
}
builtins['remprop'] = new builtin_function(std_remprop, 2, false, [CLASS_ANY, CLASS_ANY], FTYPE_EXPR);
